Proper circulatory function is essential to sustain and prolong life. From a more practical standpoint, circulatory function can be a factor affecting health care costs resulting from length of stay in the hospital, complications, hospital readmissions, and mortality. According to some professionals, ensuring the adequacy of circulatory function is one of the most important clinical goals of healthcare providers for anesthetic, perioperative, or critical care procedures. Currently, the American Society of Anesthesiology (ASA) endorses the use of the EKG monitor, systemic blood pressure (BP), pulse oximeter, and urine output (UO), known as the conventional parameters, as the basic standard of care for assessing circulatory function. However, these conventional parameters may not always provide suitable information for managing circulatory function.
Using conventional parameters may be clinically acceptable for patients with normal cardiovascular function. However, conventional parameters often provide incomplete information for patients with cardiovascular risk factors and/or comorbidities. For example, in surgical and critical care settings, managing the circulatory function of a congestive heart failure (CHF) patient with conventional parameters can lead a practitioner to deliver inappropriate amounts of intravenous (IV) fluid and/or maintain an inappropriate level of blood pressure leading to volume overload of the circulatory system of the patient. As a result of the incomplete information, many patients currently undergoing surgical procedures and/or requiring critical care medicine may not receive optimal hemodynamic management. This can lead to cardiovascular complications like acute episodes of CHF, atrial arrhythmias, length of stay in the hospital, hospital readmission after discharge, and even mortality. This result is both detrimental to the health of the patient and costly to the health care system.
This weakness in the standard of care is exacerbated by the fact that CHF, with normal (diastolic dysfunction) or reduced (systolic dysfunction) contractile function, is the leading admission diagnosis for medicine and cardiology services in the United States. Further adding to the problem is that diastolic dysfunction, often the underlying cause of CHF, is common among the baby boomer population. For individuals over 65, 53.8% suffer from some degree of diastolic dysfunction. (40.7% mild and 13.1% moderate or severe). The number of individuals over 65 has been projected to increase by 50% from 2000 to 2020 and as a result, the baby boomer population is recognized as a driving force for healthcare services.
Conventional circulatory function parameters may provide incomplete information for patients with cardiovascular risk factors and/or comorbidities. CHF is an example of one of those conditions and is also a common condition among the baby boomer population and the population as a whole. The health related and economic costs associated with complications, readmissions, and mortality rates need to be addressed. Accordingly, there is a need for a more capable system for managing the hemodynamics of patients.